Configuration, definition formulas

Application of Stirling s formula to equation 5.191 and comparison with the configurational state of pure components lead to the definition of a configurational entropy of mixing term in the form... 

It is called an a-amino acid because the amino group is attached to the a (or number 2) carbon atom. To indicate its three-dimensional structure on a flat piece of paper, the bonds that project out of the plane of the paper and up toward the reader are often drawn as elongated triangles, while bonds that lie behind the plane of the paper are shown as dashed lines. The isomer of alanine having the configuration about the a-carbon atom shown in the following structural formulas is called S-alanine or L-alanine. The isomer which is a mirror image of S-alanine is R-alanine or D-alanine. Pairs of R and S compounds (see Section B for definitions) are known as enantiomorphic forms or enantiomers. 

Clebsch-Gordan coefficients have already occurred several times in our considerations in the Introduction (formula (2)) while generalizing the quasispin concept for complex electronic configurations, while defining a relativistic wave function (formulas (2.15) and (2.16)), in the addition theorem of spherical functions (5.5) and in the definition of tensorial product of two tensors (5.12). Let us discuss briefly their definition and properties. There are a number of algebraic expressions for the Clebsch-Gordan coefficients [9, 11], but here we shall present only one ... 

The logic flow of data Definition and handling of variables and I/O Control algorithms and formulae Coded/configured calculations... 

In order to calculate the entropy, we use its fundamental definition [Eq. (5)]. For distinguishable particles (Boltzmann statistics), we use formula (8) for the number of configurations ... 

The indispensable contribution of crystallography has been to establish the molecular formulas, the stereoconfigurations, and the absolute configurations of five quite different toxins representative of the five major classes of dendrobatid alkaloids. Each of the five substances had unexpected and novel chemical bonding. Knowledge of the structures from crystal structure analyses led to reevaluations of the spectral properties of analogs and congeners and to the definitions of the structures of more than 200 dendrobatid alkaloids. 

Based upon an approximate assumption that all the energies Em lie within a definite intermediate configuration, 41 5d for example, Judd [117] completed the summation over m, with closure over the operators D(1) and HCf to give the following formula ... 

The Lewis method of formulation therefore shows more isomers than actually exist. The minimum in curve C is an energy minimum with respect to both electron distribution and atomic configuration, and hence represents a definite compound but one that cannot be represented by a single Lewis formula. This compound is a meso-meric one. We have represented its energy and atomic configura-... 

Chiral, definition of, 260 Chiral axis. See Stereogenic axis Chiral center. See Stereogenic center Chiral drugs, 273 Chiral molecules, 259—263, 290 absolute configuration, 267, 292 Fischer projection formulas, 271-272, 278, 280, 292-293... 

---